This invention relates to fluid densitometers.
Acoustic resonance densitometers are now well known for use in measuring fluid density. Typically, a sample chamber is formed as part of a mechanical resonator system which is driven into self resonance by incorporating appropriate transducers and an electronic amplifier in a closed loop positive feedback circuit. The sample chamber is often a straight or U shaped tube through which the sample flows.
The commercially available systems are expensive even in the case of low resolution instruments. This is to a large extent because the mechanical resonators are difficult and expensive to make, it being necessary to control the acoustic properties within very close limits. There are typically large numbers of machining and heat treatment steps with high reject rates in quality control.
It is an object of this invention to provide a liquid densitometer which is of low cost yet which offers a reasonable resolution and reproducibility in measurements.